Fig . 1: Map of Iran with the localities where ants were collected (black dots).

Steiner & al. 2006, Csosz & al. 2007). However, based on distribution maps of TetramoriumHNS ants in the western Palearctic(see Schlick-Steiner & al. 2006) we left this species in the list as TetramoriumHNS cf. caespitumHNS . The situation is similar with the old records of LasiusHNS species (see Seifert 1992), that need to be reviewed by modern keys. Nevertheless this work is beyond the scope of the present paper, so we included these species in our preliminary list without revision.

The record of DorylinaeHNS is the first record of this subfamily after the new clarification of this subfamily by Bolton(2003).

Distribution of records

Regarding the geographical distribution of the species records that had been examined in this study, we found a mismatching between the area of the locations that had been studied and the respective number of species that had been found there: e.g., 34 species of a total of 109 species were collected in natural or disturbed habitats of Tehran province, though the territory of this province is less than 2 % of the territory of the country. Fifteen species were recorded from the Caspian forest region in the north of Iran that covers only 4 % of the country. Eight species were found in Zagros Mountains forest-steppe ecoregion (about 20 % of entire area of the country). From the south of Iran altogether 34 species were reported. In contrast, there are only a few records from the wide Elburz Range forest-steppe and the Eastern Anatoloian Mountains in the north and northwest of Iran, or from eastern parts and the centre of the country that lie in the vast Central Persian desert basin. There are no species records at all from the Eastern Iran mountain woodlands, the Kopet Dag woodlands, Kopet Dag semi desert, Azerbaijan shrub desert and steppe, and the desert and semi-desert areas in the centre and the east of Iran that comprise more than 50 % of the area of the country.

Discussion

Although the first reports on Iranian ants were published more than 100 years ago, the ant fauna of this country remains poorly known. Most of the records are from the north of Iran, but many of these samples were collected in disturbed environments near human settlements that comprise only a few percent of the country's surface area. There are only a few species reports from the extensive natural habitats of the north, for example from the Caspian deciduous forests. The latter should have a rich ant fauna due to old geological age of that forest region: it has been covered with forests since the late Tertiary period (Zohary 1973). As a result, Tertiarian elements could have survived, as it is known for the adjacent Talysh and Zuvand districts in south-eastern Azerbaijan (Arnoldi 1930, 1948).

Among the other regions that have been investigated only cursorily is the Nubo-Sindian desert and semi desert ecoregion in the south and the southeast of the country. These areas are particularly interesting faunistically, as they are close to the boundaries of the Oriental and Afrotropical zoogeographic regions. Four important ecoregions that comprise a large part of the Irano-Anatolian biodiversity

hotspot have not been studied at all. These are the Eastern Anatolian Mountains, Elburz forest-steppe, Kopet Dag woodlands and forest-steppe, and Zagros Mountains forest-steppe. For comparison, the well studied myrmecofauna of the Turkmenistan's part of the Kopet Dag is one of the richest local ant fauna in Central Asia (Dlussky & Zabelin1985, Dlussky & al. 1990).

This scarcity of data, especially from the border regions, does not permit to make a proper zoogeographical analysis of the Iranian ant fauna at present. However, in the future, when sufficient material will have been sampled, the Iranian myrmecofauna needs to be compared with those of the adjacent regions, e.g., Turkey, Armenia, Azerbaijan, Turkmenistan, Afghanistan, and Arabian Peninsula. Similarly, the presence of North African elements in Iran (e.g., Camponotus fellah Dalla TorreHNS , 1893 or Crematogaster inermis MayrHNS , 1862) demonstrates a relation of the Iranian and North African desert faunas that has to be confirmed by more intensive sampling.

Almost half of the recorded species in the Iranian checklist belong to the genera CamponotusHNS , MessorHNS and CataglyphisHNS . Similar faunistic patterns are found in other arid Asian regions, e.g., Turkmenistan (Dlussky & al. 1990) and Saudi Arabia (Collingwood 1985, Collingwood& Agosti 1996). The main reason for the high diversity of these genera are the environmental conditions in Iran that comprise mainly arid and semi arid areas, the preferred habitats of MessorHNS , CataglyphisHNS and many CamponotusHNS species (Dlussky 1981, Dlussky & al. 1990, Höll- dobler & Wilson 1990, Andersen & Clay 1996, Andersen& spain 1996).

The second reason for the dominance of those three genera in ant collections may be artificial: their members are large and can be easily collected by anyone. In the majority of the former studies, "direct hand collecting" was the main method. For this reason small-sized and cryptic ants (e.g., LeptanillinaeHNS , AmblyoponinaeHNS , DacetiniHNS , etc.) are under-represented in the investigated material. Furthermore, social parasites are also missing in the presented species list of Iran. To overcome this sampling bias and to establish a reliable species list, thorough investigations of ant diversity in all parts of Iran are urgently needed. They should be conducted by standard sampling methods, like direct collecting from ant nests, pitfall traps, bait trapping and litter extraction with Winkler collectors (see Agosti & Alonso

2000).

At last, we have to emphasize that the Iranian ant fauna seems to be one of typically Palaearctic character. If we exclude the introduced species mentioned above, native members of only four tropical (Oriental or Afrotropical) genera are found in Iran: Aenictus dlusskyi ArnoldiHNS , 1968, Anochetus evansi CrawleyHNS , 1922, DorylusHNS sp., and Polyrhachis lacteipennis Smith, F., 1858. This dominance of

Palaearctic ant genera will probably persist in a more comprehensive species list to be presented in the future.

Acknowledgements

We thank Hamidreza Hajiqanbar for collecting and sending the material of two ant species, Crematogaster bogojawlenskii and Tetramorium inerme that were new to Iran. We thank Dr. Bernhard Seifert for his taxonomic comments, Dr. Cedric A. Collingwood for the identification of many specimens and Dr. Dubovikov for checking Forel's vouchers in ZISP. We are indebted to John Fellowes, an anonymous referee and the editors for their useful suggestions towards the improvement of our paper. We thank Doug Johns and Bryson Voirin for language correction of the first and the second versions of the text, respectively.